Because of the documented loss of three canopies that I personally know of I have compiled this web page on the care of the canopy. I spent 5 years with an SF260 and never inspected the canopy release mechanism for fear of accidently damaging the canopy. When I had N406FD painted I removed the canopy in 15 seconds and spent 30 minutes inspecting the canopy when I picked up the plane. I did not remove the front cowling inspection plates because this is so time consuming and offers little extra protection. However, my real reason for not removing the front panels was the new paint and my desire not to damage it.


Note the sliding pin #8. It holds the canopy rails on. It is very simple to remove the canoy and rails. Getting it back on is another matter. With the two barber pole release handles it is easy. If you have the single center console release you must remove the square inspection plates #1 and then use a lever to push the control rods rearward. Once fully engaged you can see the sliding pin at the rear of the locking block.

Once the canopy and rails are removed from the plane simply slide the rail and rollers rearward. You can eventually work the rollers off of the frame.

The 2cm steel tube for the canopy frame must roll between these two rollers. If they get grime in them they will freeze up and then the frame must slide over the rollers. This will make the canopy difficult to open and shut. The roller support must be removed so you can clean the rollers. Use a 7/32 socket to remove the selflocking nuts. Now you can use a 5/16 socket to remove the roller nuts. The plastic rollers have a central steele sleeve which should be cleaned out and do not use grease for a lubricant. Just use graphite.

Note the locking tab on the bottom of the rail. This is steele and strong enough to hold the canopy in place.

This is at the rear of the left canoy rail. The bottom roller is difficult to see until you remove the frame. To remove the bottom roller you must remove the support block so you can get a screw driver into the slot.

#1 is the block that holds the locking pin.
#2 is the locking pin. It is not in very far. The block will come to the right when you lever the control rod rearward. The tab to the right is part of the canopy rail.
#3 is where you should see the protruding tip of the locking pin.
#4 is the canopy control rod. The bolck is held inplace with a through bolt so its position is fixed relative to the other locking pin blocks.
The above picture is made with no mirrors. Even with the dental mirror I could never see the pin this clearly. I worked for two hours to remove all of the inspection plates, change the rusty screws to stainless steel, and inspect the locking pins to be positive that each had come through into position #3.

Here the handle is out enough to release the canopy. If you get a chance to buy a plane with this modification you are indeed lucky. I plan to hardwire the handle in place so some child does not jettison the canopy by mistake.



Look above at the plate #25. If you remove this plate which is on the fuselage just in front of the canopy you can see can #19 which has bolt #36 going through the top extension. You can force this point back about 3 or 4mm giving a more secure attachment for the canopy rails. The twisting movement in the release shaft keeps the rod #35 from going back to its full extent. One would think that pushing on the release handle hard enough would fully engage the lacoing pins but it does not.

This is the canopy release mechanism on the SF260D. I have seen some C models that were modified at the factory to have the canopy release handles in the center console. This is a superior location for the handle and I would not go back to the older release mechanism.

comments from our readers.

Wjvitale@aol.com
Date: Sun, 24 Mar 2002 12:52:05 EST
Subject: Re: the canopy release mechanism

Yet more great information from the encyclopedic recesses of Dr. Dudley!
Interesting to note that in-flight jettison of the canopy (commanded or accidental) always results in a destructive crash of the canopy into the tail assembly. Part of the framework remains imbedded in the vertical stabilizer while the plexiglass shatters into oblivion. New canopy is about 14K plus the cost of repairs to the tail section.

Worse yet, in the one incident that I have first hand knowledge of, the canopy released on the left side first then swung over to impact the right side of the fuselage before striking the tail section. More expense yet!

Best, Bill

comment #2:
hi Dudley,

I reread the chapter about the canopy emergency release mechanism from the copied manual you send me many years ago. It took me some time to understand what the manual was trying to say.

If I look at the photo of the inspection hole, the distance between the lockpin (no. 1) and the head of the bushing in the support should be 1.5 mm (0.06 in) maximum. In the SF.260C manual page 2-27 figure 2-18/F.

They also in the manual safety wire the right hand release lever with 0.51 mm (0.02 in) dia wire Spec. MS20995CU. In the air force we call it break wire.

In the photo you may want to ad an arrow saying which way is forward and/or up. I reckon this is a photo of an inspection hole on the right hand side of the fuselage.

I did not find it with the FAA but the Australian CASA issued AD/SM-260-12 Canopy Latch Assembly-Modification, dated 8/79. It gives following information.
Applicability: All models F260, F260B and F260C fitted with canopy latch assembly p/n. 260-11-129-11
Document: SIAI Marchetti SB No. 260B29
Compliance: before 30 December 1979
Background: At airspeeds in the vicinity of VNE (235 kts) the canopy lifts and inadvertent unlocking of the canopy may occur.
---

Although this is not applicable to your SF.260D, it may be of interest to other SF.260 owners to see if SB 260B29 was ever performed on their aircraft.

regards,
hendrik van der veen

The above is "for information only"; please check yourself for the correct papers or manuals applicable for your SF.260.

NOTE:
Hendrik is a crew chief on an F16 and I consider his advice to be worth more than gold.

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